Knife lockout mechanisms for surgical instrument

ABSTRACT

A cartridge assembly for use with a surgical stapling instrument is disclosed. The cartridge assembly includes a channel, a cover, a staple cartridge and a knife. The channel includes a protrusion thereon. The cover is configured for mechanical engagement with the channel and includes a blocking member and a surface defining a plane. At least a portion of the blocking member is configured to move away from the plane upon contact with the protrusion. The staple cartridge is configured for mechanical engagement with the cover. The blocking member is configured to substantially prevent distal translation of the knife after the knife has been translated proximally past a predetermined position.

BACKGROUND

1. Technical Field

This present disclosure relates to a surgical instrument having jawsthat are movable between open and closed positions, and moreparticularly to a surgical instrument having a knife bar.

2. Background of Related Art

Surgical devices wherein tissue is first grasped or clamped betweenopposing jaw structure and then joined by surgical fasteners are wellknown in the art. In some instruments, a knife is provided to cut thetissue which has been joined by the fasteners. The fasteners aretypically in the form of surgical staples but two part polymericfasteners can also be utilized.

Instruments for this purpose may include two elongated members which arerespectively used to capture or clamp tissue. Typically, one of themembers carries a staple cartridge that houses a plurality of staplesarranged in at least two lateral rows while the other member has ananvil that defines a surface for forming the staple legs as the staplesare driven from the staple cartridge. The stapling operation is effectedby cam bars that travel longitudinally through the staple cartridge,with the cam bars acting upon staple pushers to sequentially eject thestaples from the staple cartridge.

SUMMARY

The present disclosure relates to a cartridge assembly for use with asurgical stapling instrument. The cartridge assembly includes a channel,a cover, a staple cartridge and a knife. The channel includes aprotrusion thereon. The cover is configured for mechanical engagementwith the channel and includes a blocking member and a surface defining aplane. At least a portion of the blocking member is configured to moveaway from the plane upon contact with the protrusion. The staplecartridge is configured for mechanical engagement with the cover. Theblocking member is configured to substantially prevent distaltranslation of the knife after the knife has been translated proximallypast a predetermined position.

The present disclosure also relates to a surgical stapling instrumentincluding a frame, an elongate portion extending distally from the frameand defining a longitudinal axis, and a cartridge assembly. Thecartridge assembly is disposed in mechanical cooperation with theelongate portion and includes a surface defining a plane, a protrusion,a blocking member and a knife. At least a portion of the blocking memberis configured to move away from the plane upon engagement with theprotrusion. The knife is configured for translation with respect to thesurface. The blocking member is configured to substantially preventdistal translation of the knife after the knife has been translatedproximally past a predetermined position.

DESCRIPTION OF THE DRAWINGS

Various embodiments of the presently disclosed surgical staplingapparatus are disclosed herein with reference to the drawings, wherein:

FIG. 1 illustrates a side view of a surgical instrument in accordancewith an embodiment of the present disclosure;

FIG. 2 illustrates a partial cross-sectional view of a frame of thesurgical instrument of FIG. 1 showing a clamp handle in an openposition;

FIG. 3 illustrates a partial cross-sectional view of the frame of FIG. 2showing the clamp handle in an approximated position;

FIG. 4 illustrates a partial cross-sectional view of the frame of FIG. 2with portions of the frame omitted;

FIG. 5 illustrates a distal portion of the surgical instrument of FIG. 1showing jaw members in an open position in accordance with an embodimentof the present disclosure;

FIG. 6 illustrates an enlarged view of the part of the distal portion ofthe surgical instrument indicated in FIG. 5;

FIG. 7 illustrates a distal portion of the surgical instrument of FIG. 1showing the jaw members in an approximated position in accordance withan embodiment of the present disclosure;

FIG. 8 illustrates an enlarged view of the part of the distal portion ofthe surgical instrument indicated in FIG. 7;

FIG. 9 illustrates an enlarged cross-sectional view of a distal portionof an embodiment of the surgical instrument of the present disclosureshowing a knife connection in an unlinked position in accordance with anembodiment of the present disclosure;

FIG. 10 illustrates the knife connection of FIG. 9 in a linked position;

FIG. 11 illustrates a cross-sectional view of a knife connection in anunlinked position according to an embodiment of the present disclosure;

FIG. 12 illustrates the knife connection of FIG. 11 in a linkedposition;

FIG. 13 illustrates a cross-sectional view of a knife connection in anunlinked position according to an embodiment of the present disclosure;

FIG. 14 illustrates the knife connection of FIG. 13 in a linkedposition;

FIG. 15 illustrates a top, cross-sectional view of a knife connection inan unlinked position according to an embodiment of the presentdisclosure;

FIG. 16 illustrates the knife connection of FIG. 15 in a linkedposition;

FIG. 17 illustrates a side view of the knife connection of FIG. 16;

FIG. 18 illustrates an exploded view of a cartridge assembly accordingto an embodiment of the present disclosure; and

FIG. 19 illustrates a partial, cross-sectional view of the cartridgeassembly of FIG. 18.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the presently disclosed surgical instrument are describedin detail with reference to the drawings wherein like numerals designateidentical or corresponding elements in each of the several views. As iscommon in the art, the term “proximal” refers to that part or componentcloser to the user or operator, e.g., surgeon or physician, while theterm “distal” refers to that part or component farther away from theuser.

Referring to FIG. 1, an embodiment of a surgical instrument 100 of thepresent disclosure is illustrated. Surgical instrument 100 of thisembodiment includes a frame 110, a clamp handle 120, a firing handle130, an elongate portion 140 and an end effector 150. Elongate portion140 defines a longitudinal axis “X-X” for surgical instrument 100. Frame110 is of an overall size and shape convenient for being held in thehand. Clamp handle 120 and firing handle 130 are both pivotally mountedto frame 110 for actuation between open and closed positions.

An example of various aspects of the present disclosure, including theframe, clamp handle, and firing handle, are disclosed in commonly-ownedU.S. Pat. No. 5,318,221, the disclosure of which is hereby incorporatedby reference herein, in its entirety. Certain aspects of the presentdisclosure, including actuation of end effector 150, is disclosed incommonly-owned U.S. Pat. No. 6,953,139 to Milliman et al., the entirecontents of which are hereby incorporated by reference herein.

As discussed in greater detail below, end effector 150 includes two jawmembers—an anvil 160 and a cartridge assembly 170. Anvil 160 andcartridge assembly 170 extend from a distal portion of elongate portion140. At least one of anvil 160 and cartridge assembly 170 are pivotablymovable in relation to the other. Anvil 160 includes a tissue-contactingsurface with staple forming depressions thereon (not explicitly shown inthe illustrated embodiments). Cartridge assembly 170 includes aplurality of surgical fasteners therein (not explicitly shown in theillustrated embodiments), which are ejectable through tissue and intoanvil 160.

A replaceable staple cartridge (or loading unit) may be used withsurgical instrument 100 of FIG. 1. The replaceable staple cartridge mayhouse a plurality of staples arranged in at least two lateral rows andmay be mountable in a cartridge channel 210 of cartridge assembly 170.Examples of loading units for use with a surgical stapling instrumentare disclosed in commonly-owned U.S. Pat. No. 5,752,644 to Bolanos etal. the entire contents of which are hereby incorporated by referenceherein.

A portion of a drive assembly 300 is illustrated in FIGS. 2-4. Driveassembly 300 of this embodiment includes a drive beam 310. At least apartial actuation of clamp handle 120 is configured to translate drivebeam 310 longitudinally to approximate anvil 160 and cartridge assembly170 with respect to one another. At least a partial actuation of firinghandle 130 is configured to translate a firing rod 320 (discussed ingreater detail below) longitudinally to eject surgical fasteners (e.g.,staples) from cartridge assembly 170 and/or to cut tissue. The firingrod 320 is arranged in the elongate portion 140 and is connected toknife 400 as discussed below. The firing rod 320 is arranged alongside,or concentrically with the drive beam 310.

To clamp tissue, clamp handle 120 is pivoted downward (in the directionof arrow “A” in FIG. 2) towards frame 110. Clamp handle 120 is connectedto a handle link 122 such that drive beam 310 moves longitudinally whenclamp handle 120 is pivoted closed. This distal longitudinal movementcauses a portion of drive beam 310 (e.g., I-beam or actuation portion330) to contact a camming surface 152 of end effector 150 forcing atleast one of anvil 160 and cartridge assembly 170 towards the other.Further details of the clamp handle 120 and drive beam 310 are disclosedin commonly-owned U.S. Pat. No. 5,318,221 to Green et al., the entirecontents of which are hereby incorporated by reference herein.

When the surgeon is ready to emplace fasteners and cut tissue, firinghandle 130 is actuated, which translates firing rod 320 longitudinally(e.g., distally). An actuation sled may be positioned distally of thedistal end of firing rod 320 such that the distal longitudinal movementof firing rod 320 advances the actuation sled in the distal direction.After actuation, firing handle 130 is released and returns to itsoriginal position. Further details of firing fasteners and theretraction of firing handle 130 are disclosed in U.S. Pat. No. 5,318,221to Green et al., previously incorporated by reference.

With continued reference to FIGS. 2-4, further details of clamp handle120 and internal parts of frame 110 are shown according to an embodimentof the present disclosure. Here, a proximal portion 124 of handle link122 (e.g., a monolithically formed link) is pivotably engaged with clamphandle 120 (e.g., a proximal portion thereof) and a distal portion 126of handle link 122 is pivotably engaged with a proximal portion 312 ofdrive beam 310. A biasing member 180 is illustrated (see FIG. 4), whichis configured to bias drive beam 310 proximally (which biases the jawmembers in an open position). A proximal portion of biasing member 180is disposed in mechanical cooperation with frame 110 (e.g., via pin 182)and a distal portion of biasing member 180 is in mechanical cooperationwith proximal portion 312 of drive beam 310 (see FIG. 4). As can beappreciated, at least a partial actuation (i.e., movement in thedirection of arrow “A”) of clamp handle 120 forces distal portion 126 ofhandle link 122 distally, which causes drive beam 310 to be distallytranslated against the bias of biasing member 180. As discussed above,distal translation of drive beam 310 causes approximation of the jawmembers to clamp tissue therebetween.

With specific reference to FIGS. 2 and 3, surgical instrument 100 ofthis embodiment includes a latch structure 190 disposed in mechanicalcooperation with at least one of frame 110 and clamp handle 120. Forexample, latch structure 190 may include a first portion 192 disposed onclamp handle 120 and a second portion 194 disposed on frame 110, suchthat actuation of clamp handle 120 (e.g., a full actuation) causes firstportion 192 to engage with second portion 194 to releasably maintainclamp handle 120 in a closed position. Further, a release mechanism 196may be disposed on a portion of surgical instrument 100 (e.g., clamphandle 120) such that applying pressure to release mechanism 196 (e.g.,upward pressure) causes clamp handle 120 to be released from its closedposition. That is, activation of release mechanism 196 causes portions192, 194 of latch mechanism 190 to disengage or unlatch from oneanother.

In an envisioned embodiment, biasing member 180 is a spring thatincludes a spring constant which is configured to prevent the jawmembers from reaching their approximated position when tissuetherebetween exceeds a predetermined thickness. An example when tissueis “too thick” is when the thickness of the tissue between the jawmembers would substantially prevent proper emplacement of fastenerstherein and/or therethrough.

In a disclosed embodiment, actuation of clamp handle 120 is alsoconfigured to provide a user with tactile feedback. For instance, theresistance a user experiences in response to actuating clamp handle 120may be proportionate to the thickness of the tissue being clampedbetween the jaw members. Thus, the user is provided with feedback (inthe form of resistance) as clamp handle 120 is actuated to approximatethe jaw members about tissue therebetween. This feedback may be directlyor indirectly proportional to the thickness of the tissue being clamp.It is further envisioned that this amount of force is insufficient toovercome the resistance provided by “too thick” tissue being positionedbetween the jaw members, thus substantially preventing a user from clamptissue that is “too thick.”

With specific reference to FIG. 2, in its non-actuated or open position,clamp handle 120 (including handle link 122 and various pivot points) isconfigured to have a relatively low height from the longitudinal axis.Such a relatively small distance provides the overall surgicalinstrument 100 with a smaller profile, which is generally a desirablefeature, as the instrument is less bulky and thus easier to handle.Additionally, it is envisioned that a user can actuate this “lowprofile” clamp handle 120 with his or her thumb of the same hand thatthe user uses to actuate movable handle 130 to fire staples, forexample. Thus, clamp handle 120 is configured and dimensioned tofacilitate one-handed operation of surgical instrument 100.

Referring now to FIGS. 5-8, an embodiment of the present disclosurerelating to approximating jaw members is shown. In this embodiment, endeffector 150 includes a pair of camming surfaces 152 a and 152 b. FIGS.5 and 6 illustrate the jaw members in an open (i.e., non-approximated)position. Here, actuation portion 330 (e.g., an upper horizontal portionof an I-beam) of drive beam 310 is in a first, proximal position. Asdiscussed hereinabove, approximation of clamp handle 120 causesactuation portion 330 of drive beam to translate distally. Upon distaltranslation of drive beam 310, actuation portion 330 contacts distalcamming surface 152 a, which causes approximation of the jaw members(e.g., cartridge assembly 170 moves towards a stationary anvil 160).FIGS. 7 and 8 illustrate the result of at least a partial actuation ofclamp handle 120, i.e., actuation portion 330 in a distal position andthe jaw members in an approximated position.

Once the jaw members are approximated, a user can, for instance, atleast partially actuate firing handle 130 to advance the firing rod andeject staples from cartridge assembly 170. The firing handle isdesirably biased toward its initial position so that after firing, thefiring rod and actuation portion 330 are retracted. Prior to theejection of staples, the user can raise clamp handle 120 (e.g., in thesubstantial direction of arrow “B” in FIG. 3) to retract drive beam 310and cause actuation portion 330 to move proximally and contact proximalcamming surface 152 b. As actuation portion 330 of drive beam 310contacts proximal camming surface 152 b, the jaw members open withrespect to each other (e.g., cartridge assembly 170 moves away fromanvil 160). As shown, distal camming surface 152 a and proximal cammingsurface 152 b may be adjacent one other, thus forming a V-like shape.

In the illustrated embodiment, the movable jaw member (e.g., cartridgeassembly 170) also includes a lip 154 disposed on a proximal portionthereof. Lip 154 is raised above camming surface 152 b and is configuredto help prevent actuation portion 330 of drive beam 310 from beingtranslated too far proximally.

Additionally, the movable jaw member is shown having a substantiallyflat surface 156 (i.e., substantially parallel with the longitudinalaxis when the jaw members are approximated) adjacent to and distally ofdistal camming surface 152 a (see FIG. 6). In this configuration,actuation portion 330 of drive beam 310 may continue to translatedistally after contacting distal camming surface 152 a (and after thejaw members have been at least partially approximated) and may engagesurface 156. It is envisioned that engagement between actuation portion330 and surface 156 may help maintain the jaw members in theapproximated position.

Additionally, while not explicitly illustrated herein, it is envisionedthat surgical instrument 100 of the present disclosure does not includea clamp handle. In such an embodiment, a partial actuation of firinghandle 130 can be used to approximate jaw members and a further, morecomplete, actuation of firing handle 130 fires staples, for instance.The firing handle, in these embodiments, has a pawl that is biased intoengagement with a toothed rack attached to the drive beam. Multipleactuations of the firing handle are used to advance the drive beam. Theinitial advancement of the drive beam closes the jaw members. Withcontinued actuation of the firing handle, the actuation portion 330continues to travel distally, firing the staples. The cartridge assemblyand anvil include a slot for permitting the actuation portion 330 totravel toward the distal end of the jaw members. The handle assemblydisclosed in U.S. Pat. No. 6,953,139 to Milliman et al., the entirecontents of which are hereby incorporated by reference herein, may beused. In this embodiment, the actuation portion 330 is connected to theknife member, which pushes the sled 650 to fire the staples.

Referring now to FIGS. 9-17, embodiments of the present disclosurerelating to various knife/firing rod connections are shown. In theseembodiments, the structure of a portion of firing rod 320 and/or aportion of a knife 400 is configured to enable connection between firingrod 320 and a single-use knife 400, thus enabling a fresh knife 400 tobe used for each firing of surgical instrument 100.

With particular reference to FIGS. 9 and 10, a first embodiment of aknife/firing rod connection is shown. Specifically, FIG. 9 illustratesfiring rod 320 a in a first, proximal position where a loading unit, orreplaceable cartridge, has been inserted into the cartridge assembly andfiring rod 320 a and knife 400 a are unlinked. FIG. 10 illustratesfiring rod 320 a in a second, distal position where firing rod 320 a andknife 400 a are linked. Firing rod 320 a and knife 400 a of thisembodiment are configured such that distal movement of firing rod 320 acauses a distal end 322 a thereof to link with knife 400 a when endeffector 150 is engaged with elongate portion 140 of surgical instrument100. Additionally, proximal movement of firing rod 320 a causes knife400 a (which is linked thereto) to move proximally. Further, firing rod320 a and knife 400 a are configured to become unlinked with each otherwhen firing rod 320 a has been translated proximally to a predeterminedposition (e.g., corresponding to when firing handle 130 has beensubstantially fully retracted in the direction of arrow “C” in FIG. 1).

In the unlinked position (i.e., where there is a sufficient distancebetween a surface 401 a of knife 400 a and a surface 323 a of distal end322 a of firing rod 320 a (see FIG. 9)), a user may replace knife 400 awith a fresh knife by replacing cartridge assembly 160, for example.While the illustrated embodiments illustrate the jaw members in theapproximated position, it is envisioned that a user may remove and/orreplace knife 400 a when the jaw members are in an open position.

Further details of the interaction between firing rod 320 a and knife400 a are described herein with continued reference to FIGS. 9 and 10.As firing rod 320 a is advanced distally, at least one projection 142(e.g., a pair of projections, a radially-disposed projection, etc.)disposed on elongate portion 140 is configured to move at least aportion of firing rod 320 a transverse to the longitudinal axis (e.g.,in the direction of arrow “D” in FIG. 10). For instance, a projection143 can contact a ramp 324 a of firing rod 320 a. As can be appreciatedwith regard to FIGS. 9 and 10, the combination of the distal movementand the transverse movement causes distal end 322 a (e.g., J-shaped) offiring rod 320 a to engage (e.g., link) a proximal portion 402 a (e.g.,J-shaped) of knife 400 a. Correspondingly, as firing rod 320 a istranslated proximally, at least one projection 142 is configured to moveat least a portion of firing rod 320 a transverse to the longitudinalaxis (e.g., in the direction of arrow “E” in FIG. 9). For instance,projection 142 can contact a ramp 326 a formed on firing rod 320 a.Thus, the combination of the proximal movement and the transversemovement causes distal end 322 a of firing rod 320 a to disengage (e.g.,unlink) proximal portion 402 a of knife 400 a.

With particular reference to FIGS. 11 and 12, a second embodiment of aknife/firing rod connection is shown. Specifically, FIG. 11 illustratesthe jaw members in an open position where knife 400 b is not engaged orlinked with a connector 360 disposed distally of and adjacent firing rod320 b. FIG. 12 illustrates the jaw members in an approximated positionwhere knife 400 b is engaged or linked with connector 360. Connector 360and knife 400 b are configured such that when the jaw members are in theopen position, connector 360 and knife 400 b are unlinked (FIG. 11),thus allowing the cartridge (including knife 400 b) to be removed. Whenthe jaw members are in an approximated position (FIG. 12), a surface ofthe anvil jaw member contacts the knife 400 b, rotating knife 400 b sothat connector 360 and knife 400 b are linked, such that proximal anddistal translation of firing rod 320 (and thus connector 360) results inproximal and distal translation of knife 400 b, respectively. When thejaw members are approximated, the cartridge cannot be removed fromsurgical instrument 100, as can be appreciated with reference to FIG.12.

In the embodiment shown in FIGS. 11 and 12, connector 360 includes ahook-like portion that is configured to engage hook-like portion ofknife 400 b. Connector 360 is shown having a substantial J-shape, butany suitable shapes can be used for knife 400 b and connector 360.

It is envisioned that connector 360 is movable (e.g., pivotable,swivelable, etc.) with respect to the distal end of firing rod 320. Forexample, when the jaw members are moved towards their open position, aproximal portion 402 b of knife 400 b may contact an upper portion 362of connector 360 to pivot/swivel upper portion 362 distally, thuscreating enough space (or more space) for knife 400 b to be removed fromsurgical instrument 100. Likewise, when the jaw members areapproximated, upper portion 362 of connector 360 may pivot/swivelproximally, thus linking (or further linking) connector 360 with knife400 b, thus not allowing knife 400 b to be removed therefrom.Additionally, a flange 370 is shown, which may be configured to helpmaintain connector 360 in its position and/or to help upper portion 362of connector 360 move proximally.

Another embodiment of a knife/firing rod connection is illustrated inFIGS. 13 and 14. Specifically, FIG. 13 illustrates firing rod 320 c in afirst, proximal position where firing rod 320 c and knife 400 c areunlinked. FIG. 14 illustrates firing rod 320 c in a second, distalposition where firing rod 320 c and knife 400 c are linked. Firing rod320 c and knife 400 c of this embodiment are configured such that distalmovement of firing rod 320 c causes a distal end 322 c thereof to linkwith knife 400 c when end effector 150 is engaged with elongate portion140 of surgical instrument 100.

More specifically, this embodiment of knife/firing rod connectionincludes a spring element 500 (e.g., a leaf spring) disposed inmechanical cooperation with knife 400 c. A proximal portion 502 (e.g.,being substantially J-shaped) of spring element 500 is biased towards aknife axis K-K. Here, distal movement of firing rod 320 c urges proximalportion 502 of spring element 500 outwardly (i.e., away from knife axisK-K). The firing rod 320 includes an aperture 321 for receiving thespring element 500. Accordingly, proximal portion 502 of spring element500 is temporarily secured to firing rod 320 c. Thus, continued distaltranslation of firing rod 320 c causes distal translation of knife 400c. Further, proximal translation of firing rod 320 c causes proximaltranslation of knife 400 c until firing rod 320 c reaches apredetermined location (e.g., corresponding to when firing handle 130has been substantially fully retracted in the direction of arrow “C” inFIG. 1) where firing rod 320 c disengages from spring element 500.Desirably, the shape of the aperture 321 and spring element 500 (orspring elements 500) is such that the spring element 500 is biasedoutwardly upon removing the cartridge from the device, disconnecting thefiring rod 320 from the knife 400.

With particular reference to FIGS. 15-17, a fourth embodiment of aknife/firing rod connection is shown. Specifically, FIG. 15 illustratesfiring rod 320 d in a first, proximal position where firing rod 320 dand knife 400 d are unlinked. FIG. 16 illustrates firing rod 320 d in asecond, distal position where firing rod 320 d and knife 400 d arelinked. FIG. 17 is a side view of FIG. 16. Firing rod 320 d and knife400 d of this embodiment are configured such that distal movement offiring rod 320 d causes a distal end 322 d thereof to link with knife400 d when end effector 150 is engaged with elongate portion 140 ofsurgical instrument 100. Additionally, proximal movement of firing rod320 d causes knife 400 d (which is linked thereto) to move proximally.Further, firing rod 320 d and knife 400 d are configured to becomeunlinked with one another when firing rod 320 d has been translatedproximally to a predetermined position (e.g., corresponding to whenfiring handle 130 has been substantially fully retracted in thedirection of arrow “C” in FIG. 1). The distal end 322 d and receptacle402 d of knife 400 d are shaped so that the distal end 322 d is biasedoutwardly upon removing the cartridge from the device, disconnecting thefiring rod 320 from the knife 400.

In the unlinked position (FIG. 15), a user may replace knife 400 d witha fresh knife by replacing cartridge assembly 160, for example. It isenvisioned that the configuration of the end effector and firing rod 320d allows a user to remove and/or replace the cartridge when the jawmembers are in an open and/or approximated position.

Further details of the interaction between firing rod 320 d and knife400 d are described herein with continued reference to FIGS. 15 and 16.The connection can be formed as the distal end 322 d resiliently snapsinto the receptacle 402 d. Alternatively, as firing rod 320 d isadvanced distally, a slope 142 d disposed on elongate portion 140 isconfigured to move distal end 322 d of firing rod 320 d transverse tothe longitudinal axis (e.g., in the direction of arrow “F” in FIG. 16)towards a receptacle 402 d in knife 400 d. Additionally, oralternatively, a slope on the elongate portion can be configured andarranged to pry the distal end 322 away from engagement with the knife.As can be appreciated with regard to FIGS. 15 and 16, the combination ofthe distal movement and the transverse movement can be used to causedistal end 322 d of firing rod 320 d to engage receptacle 402 d of knife400 d. The combination of the proximal movement and the transversemovement can be used to cause distal end 322 d of firing rod 320 d toengage receptacle 402 d of knife 400 d. Similar arrangements can be usedfor the connection between knife and firing rod shown in FIGS. 13 and14.

Additionally, it is envisioned that distal end 322 d of firing rod 320 dis biased away from knife 400 d, i.e., in the substantial direction ofarrow “G” in FIG. 15. Therefore, as firing rod 320 d is translatedproximally such that distal end 322 d is proximal of slope 142 d, distalend 322 d moves out of receptacle 402 d of knife 400 d. Thus, thiscombination of movement unlinks firing rod 320 d and knife 400 d.

With reference to FIGS. 18-19, the present disclosure also relates to acartridge assembly 600 for use with a surgical stapling instrument 100.Cartridge assembly 600 is configured to prevent a user from firing asingle-use cartridge that has already been fired. More specifically,cartridge assembly 600 is configured to lock out its knife 640 andprevent re-use of a cartridge, after the cartridge has been fired.

An assembly view of cartridge assembly 600 is shown in FIG. 18. Asshown, cartridge assembly 600 includes a channel 610, a cover 620, astaple cartridge 630 and a knife 640. Cover 620 is configured formechanical engagement (e.g., a snap-fit connection) with channel 610.Staple cartridge 630 is configured for mechanical engagement with cover620 and knife 640 is configured for translation with respect to cover620 and cartridge. FIG. 18 also illustrates a sled 650, which isconfigured for translation with respect to cover 620 (e.g., to ejectstaples from staple cartridge 630).

As shown, channel 610 includes a protrusion 612 thereon for engagementwith a blocking member 622 (e.g., flexible finger) of cover 620. Uponengagement between channel 610 and cover 620, protrusion 612 causesblocking member 622 to move from a first position where blocking member622 is substantially parallel with a plane defined a surface 624 ofcover 620, to a second position where at least a portion of blockingmember 622 (e.g., a proximal portion 626) is spaced from the plane ofsurface 624. In its second position, blocking member 622 is configuredto substantially prevent distal translation of knife 640 after knife 640has been deployed to fire staples, and then translated proximally past apredetermined position (see FIG. 19). It is envisioned that cartridgeassembly 600 is configured to allow proximal translation of knife 640past blocking member 622 when blocking member 622 is in its secondposition. For example, the blocking member 622 may be formed as aresilient member. In the initial position of the knife, the blockingmember 622 is depressed by the knife. After the knife has been advanced,pushing the sled distally to fire staples, the knife is retracted to theposition shown in FIG. 19. The blocking member 622 resiliently lifts,engaging a surface on the knife. As can be appreciated, cartridgeassembly 600 can be used with various embodiments of surgical staplinginstrument 100 described herein.

It will be understood that various modifications can be made to thevarious embodiments of the present disclosure herein disclosed withoutdeparting from the spirit and scope thereof. For example, the surgicalstapling instrument of the present disclosure may include a singlemovable handle for performing all the functions (e.g., approximating thejaw members, firing staples, cutting tissue, opening the jaw members).It is envisioned that the single movable handle can be partiallyactuated to perform a first function and continued actuation wouldperform a second function. It is also envisioned that a first completeactuation would perform a first function and a second full actuationwould perform a second function.

Further, the disclosed surgical stapling instrument may not include anymovable handles; rather, surgical stapling instrument may be powered bymeans (e.g., battery, electrical, etc.) other than by actuation of ahandle or clamp. An example of a powered surgical stapler is disclosedin commonly-owned U.S. patent application Ser. No. 11/786,934, entitledPowered Surgical Instrument, the entire contents of which are herebyincorporated by reference herein. Additionally, the surgical staplinginstrument of the present disclosure may also have articulationcapabilities, which can move the end effector between a first positionwhere an axis of the end effector is parallel to an axis of the elongateportion, and a second position where the axis of the end effector is atan angle with respect to the axis of the elongate portion. An example ofa surgical stapling instrument with an articulatable end effector isdisclosed in commonly-owned U.S. patent application Ser. No. 11/544,203,entitled Surgical Instrument with Articulating Tool Assembly, the entirecontents of which are hereby incorporated by reference herein. Thereforethe above description should not be construed as limiting the disclosurebut merely as exemplifications of various embodiments thereof. Thoseskilled in the art will envision other modifications within the scopeand spirit of the present disclosure as defined by the claims appendedhereto.

1-18. (canceled)
 19. A cartridge assembly for use with a surgicalstapling instrument, the cartridge assembly comprising: a coverincluding a blocking member and including a surface defining a plane,the blocking member being biased towards a position where the blockingmember is substantially parallel with the plane, wherein at least aportion of the blocking member is movable out of alignment with theplane; a knife configured for translation with respect to the cover; andwherein the blocking member is configured to limit distal translation ofthe knife.
 20. The cartridge assembly of claim 19, wherein the blockingmember is configured to limit distal translation of the knife after theknife has been translated proximally past a predetermined position. 21.The cartridge assembly of claim 19, further comprising a sled configuredfor translation with respect to the cover.
 22. The cartridge assembly ofclaim 19, wherein the blocking member includes a flexible finger. 23.The cartridge assembly of claim 19, wherein the blocking member isconfigured to allow the knife to travel proximally therepast.
 24. Asurgical stapling instrument, comprising: a frame; an elongate portionextending distally from the frame and defining a longitudinal axis; acartridge assembly disposed in mechanical cooperation with the elongateportion, the cartridge assembly including: a surface defining a plane; ablocking member, at least a portion of the blocking member being biasedtowards a position where the blocking member is substantially parallelwith the plane, at least a portion of the blocking member being movableout of alignment from the plane; a knife configured for translation withrespect to the surface; and wherein the blocking member is configured tolimit distal translation of the knife.
 25. The surgical staplinginstrument of claim 24, further comprising a staple cartridge disposedin mechanical cooperation with the cartridge assembly, the staplecartridge including a plurality of spaced apart staples therein.
 26. Thesurgical stapling instrument of claim 24, further comprising a movablehandle disposed in mechanical cooperation with the frame, wherein atleast a partial actuation of the movable handle translates the knife.27. The surgical stapling instrument of claim 26, wherein at least apartial actuation of the movable handle in a first direction translatesthe knife distally and wherein at least a partial actuation of themovable handle in a second direction translates the knife proximallypast the blocking member.
 28. The surgical stapling instrument of claim24, further comprising a sled configured for translation with respect tothe surface.
 29. The surgical stapling instrument of claim 24, whereinthe blocking member includes a flexible finger.
 30. The surgicalstapling instrument of claim 24, wherein the blocking member isconfigured to allow the knife to travel proximally therepast when theblocking member is out of alignment with the plane.
 31. The surgicalstapling instrument of claim 24, further comprising a firing rodextending at least partially through the elongate portion.
 32. Thesurgical stapling instrument of claim 31, wherein the knife and thefiring rod form a knife/firing rod connection.
 33. The surgical staplinginstrument of claim 32, wherein the cartridge assembly is a replaceablecartridge assembly, the knife being removably connectable to the firingrod.
 34. A method of assembling a cartridge assembly for use with asurgical instrument, the method comprising: providing a cartridgeassembly including: a channel including a protrusion thereon; the coverincluding a blocking member and including a surface defining a plane;and a knife; engaging the cover with the channel such that at least aportion of the blocking member moves away from the plane upon contactwith the protrusion; and wherein the blocking member is configured tolimit distal translation of the knife.
 35. The method of claim 34,wherein the blocking member is biased towards a position where theblocking member is substantially parallel with the plane.
 36. The methodof claim 34, wherein the blocking member is configured to limit distaltranslation of the knife after the knife has been translated proximallypast a predetermined position.